- Changed TABLE->alias to String to get fewer reallocs when alias are used.
- Preallocate some buffers
Changed some String->c_ptr() -> String->ptr() when \0 is not needed.
Fixed wrong usage of String->ptr() when we need a \0 terminated string.
Use my_strtod() instead of my_atof() to avoid having to add \0 to string.
c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
zr
sql/event_db_repository.cc:
Update usage of TABLE->alias
sql/event_scheduler.cc:
c_ptr() -> c_ptr_safe()
sql/events.cc:
c_ptr() -> ptr() as \0 was not needed
sql/field.cc:
Update usage of TABLE->alias
sql/field.h:
Update usage of TABLE->alias
sql/ha_partition.cc:
Update usage of TABLE->alias
sql/handler.cc:
Update usage of TABLE->alias
Fixed wrong usage of str.ptr()
sql/item.cc:
Fixed error where code wrongly assumed string was \0 terminated.
sql/item_func.cc:
c_ptr() -> c_ptr_safe()
Update usage of TABLE->alias
sql/item_sum.h:
Use my_strtod() instead of my_atof() to avoid having to add \0 to string
sql/lock.cc:
Update usage of TABLE->alias
sql/log.cc:
c_ptr() -> ptr() as \0 was not needed
sql/log_event.cc:
c_ptr_quick() -> ptr() as \0 was not needed
sql/opt_range.cc:
ptr() -> c_ptr() as \0 is needed
sql/opt_subselect.cc:
Update usage of TABLE->alias
sql/opt_table_elimination.cc:
Update usage of TABLE->alias
sql/set_var.cc:
ptr() -> c_ptr() as \0 is needed
c_ptr() -> c_ptr_safe()
sql/sp.cc:
c_ptr() -> ptr() as \0 was not needed
sql/sp_rcontext.cc:
Update usage of TABLE->alias
sql/sql_base.cc:
Preallocate buffers
Update usage of TABLE->alias
sql/sql_class.cc:
Fix arguments to sprintf() to work even if string is not \0 terminated
sql/sql_insert.cc:
Update usage of TABLE->alias
c_ptr() -> ptr() as \0 was not needed
sql/sql_load.cc:
Preallocate buffers
Trivial optimizations
sql/sql_parse.cc:
Trivial optimization
sql/sql_plugin.cc:
c_ptr() -> ptr() as \0 was not needed
sql/sql_select.cc:
Update usage of TABLE->alias
sql/sql_show.cc:
Update usage of TABLE->alias
sql/sql_string.h:
Added move() function to move allocated memory from one object to another.
sql/sql_table.cc:
Update usage of TABLE->alias
c_ptr() -> c_ptr_safe()
sql/sql_test.cc:
ptr() -> c_ptr_safe()
sql/sql_trigger.cc:
Update usage of TABLE->alias
c_ptr() -> c_ptr_safe()
sql/sql_update.cc:
Update usage of TABLE->alias
sql/sql_view.cc:
ptr() -> c_ptr_safe()
sql/sql_yacc.yy:
ptr() -> c_ptr()
sql/table.cc:
Update usage of TABLE->alias
sql/table.h:
Changed TABLE->alias to String to get fewer reallocs when alias are used.
storage/federatedx/ha_federatedx.cc:
Use c_ptr_safe() to ensure strings are \0 terminated.
storage/maria/ha_maria.cc:
Update usage of TABLE->alias
storage/myisam/ha_myisam.cc:
Update usage of TABLE->alias
storage/xtradb/row/row0sel.c:
Ensure that null bits in record are properly reset.
(Old code didn't work as row_search_for_mysql() can be called twice while reading fields from one row.
Problem: Extended characters outside of ASCII range where not displayed
properly in SHOW PROCESSLIST, because thd_info->query was always sent as
system_character_set (utf8). This was wrong, because query buffer
is never converted to utf8 - it is always have client character set.
Fix: sending query buffer using query character set
@ sql/sql_class.cc
@ sql/sql_class.h
Introducing a new class CSET_STRING, a LEX_STRING with character set.
Adding set_query(&CSET_STRING)
Adding reset_query(), to use instead of set_query(0, NULL).
@ sql/event_data_objects.cc
Using reset_query()
@ sql/log_event.cc
Using reset_query()
Adding charset argument to set_query_and_id().
@ sql/slave.cc
Using reset_query().
@ sql/sp_head.cc
Changing backing up and restore code to use CSET_STRING.
@ sql/sql_audit.h
Using CSET_STRING.
In the "else" branch it's OK not to use
global_system_variables.character_set_client.
&my_charset_latin1, which is set in constructor, is fine
(verified with Sergey Vojtovich).
@ sql/sql_insert.cc
Using set_query() with proper character set: table_name is utf8.
@ sql/sql_parse.cc
Adding character set argument to set_query_and_id().
(This is the main point where thd->charset() is stored
into thd->query_string.cs, for use in "SHOW PROCESSLIST".)
Using reset_query().
@ sql/sql_prepare.cc
Storing client character set into thd->query_string.cs.
@ sql/sql_show.cc
Using CSET_STRING to fetch and send charset-aware query information
from threads.
@ storage/myisam/ha_myisam.cc
Using set_query() with proper character set: table_name is utf8.
@ mysql-test/r/show_check.result
@ mysql-test/t/show_check.test
Adding tests
Problem: Extended characters outside of ASCII range where not displayed
properly in SHOW PROCESSLIST, because thd_info->query was always sent as
system_character_set (utf8). This was wrong, because query buffer
is never converted to utf8 - it is always have client character set.
Fix: sending query buffer using query character set
@ sql/sql_class.cc
@ sql/sql_class.h
Introducing a new class CSET_STRING, a LEX_STRING with character set.
Adding set_query(&CSET_STRING)
Adding reset_query(), to use instead of set_query(0, NULL).
@ sql/event_data_objects.cc
Using reset_query()
@ sql/log_event.cc
Using reset_query()
Adding charset argument to set_query_and_id().
@ sql/slave.cc
Using reset_query().
@ sql/sp_head.cc
Changing backing up and restore code to use CSET_STRING.
@ sql/sql_audit.h
Using CSET_STRING.
In the "else" branch it's OK not to use
global_system_variables.character_set_client.
&my_charset_latin1, which is set in constructor, is fine
(verified with Sergey Vojtovich).
@ sql/sql_insert.cc
Using set_query() with proper character set: table_name is utf8.
@ sql/sql_parse.cc
Adding character set argument to set_query_and_id().
(This is the main point where thd->charset() is stored
into thd->query_string.cs, for use in "SHOW PROCESSLIST".)
Using reset_query().
@ sql/sql_prepare.cc
Storing client character set into thd->query_string.cs.
@ sql/sql_show.cc
Using CSET_STRING to fetch and send charset-aware query information
from threads.
@ storage/myisam/ha_myisam.cc
Using set_query() with proper character set: table_name is utf8.
@ mysql-test/r/show_check.result
@ mysql-test/t/show_check.test
Adding tests
Finalize the server flags after any kind of command is executed.
To avoid updating the flag multiple times, reorganize code so that
its invoked only once for each command.
sql/log_event.cc:
Explicit update after the query is executed in the slave.
sql/sql_parse.cc:
Reorganize so that the status flag is updated for any command and
not done twice for a query command.
Finalize the server flags after any kind of command is executed.
To avoid updating the flag multiple times, reorganize code so that
its invoked only once for each command.
network when a query was slow.
When a query is slow, sent a special flag to the client
indicating this fact.
Add a test case.
Implement review comments.
include/mysql_com.h:
Clear SERVER_QUERY_WAS_SLOW at end of each statement.
Since this patch removes the technique when
thd->server_status is modified briefly only to
execute my_eof(), reset more server status
bit that may remain in the status from
execution of the previous statement.
sql/protocol.cc:
Always use thd->server_status to
in net_* functions to send the latest
status to the client.
sql/sp_head.cc:
Calculate if a query was slow before
sending EOF packet.
sql/sql_cursor.cc:
Remove juggling with thd->server_status.
The extra status bits are reset at
start of the next statement.
sql/sql_db.cc:
Remove juggling with thd->server_status.
The extra status bits are reset at
start of the next statement.
sql/sql_error.cc:
Remove m_server_status member,
it's not really part of the Diagnostics_area.
sql/sql_error.h:
Remove server_status member, it's
not part of the Diagnostics_area.
The associated hack is removed as well.
sql/sql_parse.cc:
Do not calculate if a query was
slow twice. Use a status flag in thd->server_status.
tests/mysql_client_test.c:
Add a test case for Bug#57058.
Check that the status is present
at the client, when sent.
network when a query was slow.
When a query is slow, sent a special flag to the client
indicating this fact.
Add a test case.
Implement review comments.
bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ
LOCK" and bug #54673 "It takes too long to get readlock for
'FLUSH TABLES WITH READ LOCK'".
The first bug manifested itself as a deadlock which occurred
when a connection, which had some table open through HANDLER
statement, tried to update some data through DML statement
while another connection tried to execute FLUSH TABLES WITH
READ LOCK concurrently.
What happened was that FTWRL in the second connection managed
to perform first step of GRL acquisition and thus blocked all
upcoming DML. After that it started to wait for table open
through HANDLER statement to be flushed. When the first connection
tried to execute DML it has started to wait for GRL/the second
connection creating deadlock.
The second bug manifested itself as starvation of FLUSH TABLES
WITH READ LOCK statements in cases when there was a constant
stream of concurrent DML statements (in two or more
connections).
This has happened because requests for protection against GRL
which were acquired by DML statements were ignoring presence of
pending GRL and thus the latter was starved.
This patch solves both these problems by re-implementing GRL
using metadata locks.
Similar to the old implementation acquisition of GRL in new
implementation is two-step. During the first step we block
all concurrent DML and DDL statements by acquiring global S
metadata lock (each DML and DDL statement acquires global IX
lock for its duration). During the second step we block commits
by acquiring global S lock in COMMIT namespace (commit code
acquires global IX lock in this namespace).
Note that unlike in old implementation acquisition of
protection against GRL in DML and DDL is semi-automatic.
We assume that any statement which should be blocked by GRL
will either open and acquires write-lock on tables or acquires
metadata locks on objects it is going to modify. For any such
statement global IX metadata lock is automatically acquired
for its duration.
The first problem is solved because waits for GRL become
visible to deadlock detector in metadata locking subsystem
and thus deadlocks like one in the first bug become impossible.
The second problem is solved because global S locks which
are used for GRL implementation are given preference over
IX locks which are acquired by concurrent DML (and we can
switch to fair scheduling in future if needed).
Important change:
FTWRL/GRL no longer blocks DML and DDL on temporary tables.
Before this patch behavior was not consistent in this respect:
in some cases DML/DDL statements on temporary tables were
blocked while in others they were not. Since the main use cases
for FTWRL are various forms of backups and temporary tables are
not preserved during backups we have opted for consistently
allowing DML/DDL on temporary tables during FTWRL/GRL.
Important change:
This patch changes thread state names which are used when
DML/DDL of FTWRL is waiting for global read lock. It is now
either "Waiting for global read lock" or "Waiting for commit
lock" depending on the stage on which FTWRL is.
Incompatible change:
To solve deadlock in events code which was exposed by this
patch we have to replace LOCK_event_metadata mutex with
metadata locks on events. As result we have to prohibit
DDL on events under LOCK TABLES.
This patch also adds extensive test coverage for interaction
of DML/DDL and FTWRL.
Performance of new and old global read lock implementations
in sysbench tests were compared. There were no significant
difference between new and old implementations.
mysql-test/include/check_ftwrl_compatible.inc:
Added helper script which allows to check that a statement is
compatible with FLUSH TABLES WITH READ LOCK.
mysql-test/include/check_ftwrl_incompatible.inc:
Added helper script which allows to check that a statement is
incompatible with FLUSH TABLES WITH READ LOCK.
mysql-test/include/handler.inc:
Adjusted test case to the fact that now DROP TABLE closes
open HANDLERs for the table to be dropped before checking
if there active FTWRL in this connection.
mysql-test/include/wait_show_condition.inc:
Fixed small error in the timeout message. The correct name
of variable used as parameter for this script is "$condition"
and not "$wait_condition".
mysql-test/r/delayed.result:
Added test coverage for scenario which triggered assert in
metadata locking subsystem.
mysql-test/r/events_2.result:
Updated test results after prohibiting event DDL operations
under LOCK TABLES.
mysql-test/r/flush.result:
Added test coverage for bug #57006 "Deadlock between HANDLER
and FLUSH TABLES WITH READ LOCK".
mysql-test/r/flush_read_lock.result:
Added test coverage for various aspects of FLUSH TABLES WITH
READ LOCK functionality.
mysql-test/r/flush_read_lock_kill.result:
Adjusted test case after replacing custom global read lock
implementation with one based on metadata locks. Use new
debug_sync point. Do not disable concurrent inserts as now
InnoDB we always use InnoDB table.
mysql-test/r/handler_innodb.result:
Adjusted test case to the fact that now DROP TABLE closes
open HANDLERs for the table to be dropped before checking
if there active FTWRL in this connection.
mysql-test/r/handler_myisam.result:
Adjusted test case to the fact that now DROP TABLE closes
open HANDLERs for the table to be dropped before checking
if there active FTWRL in this connection.
mysql-test/r/mdl_sync.result:
Adjusted test case after replacing custom global read lock
implementation with one based on metadata locks. Replaced
usage of GRL-specific debug_sync's with appropriate sync
points in MDL subsystem.
mysql-test/suite/perfschema/r/dml_setup_instruments.result:
Updated test results after removing global
COND_global_read_lock condition variable.
mysql-test/suite/perfschema/r/func_file_io.result:
Ensure that this test doesn't affect subsequent tests.
At the end of its execution enable back P_S instrumentation
which this test disables at some point.
mysql-test/suite/perfschema/r/func_mutex.result:
Ensure that this test doesn't affect subsequent tests.
At the end of its execution enable back P_S instrumentation
which this test disables at some point.
mysql-test/suite/perfschema/r/global_read_lock.result:
Adjusted test case to take into account that new GRL
implementation is based on MDL.
mysql-test/suite/perfschema/r/server_init.result:
Adjusted test case after replacing custom global read
lock implementation with one based on MDL and replacing
LOCK_event_metadata mutex with metadata lock.
mysql-test/suite/perfschema/t/func_file_io.test:
Ensure that this test doesn't affect subsequent tests.
At the end of its execution enable back P_S instrumentation
which this test disables at some point.
mysql-test/suite/perfschema/t/func_mutex.test:
Ensure that this test doesn't affect subsequent tests.
At the end of its execution enable back P_S instrumentation
which this test disables at some point.
mysql-test/suite/perfschema/t/global_read_lock.test:
Adjusted test case to take into account that new GRL
implementation is based on MDL.
mysql-test/suite/perfschema/t/server_init.test:
Adjusted test case after replacing custom global read
lock implementation with one based on MDL and replacing
LOCK_event_metadata mutex with metadata lock.
mysql-test/suite/rpl/r/rpl_tmp_table_and_DDL.result:
Updated test results after prohibiting event DDL under
LOCK TABLES.
mysql-test/t/delayed.test:
Added test coverage for scenario which triggered assert in
metadata locking subsystem.
mysql-test/t/events_2.test:
Updated test case after prohibiting event DDL operations
under LOCK TABLES.
mysql-test/t/flush.test:
Added test coverage for bug #57006 "Deadlock between HANDLER
and FLUSH TABLES WITH READ LOCK".
mysql-test/t/flush_block_commit.test:
Adjusted test case after changing thread state name which
is used when COMMIT waits for FLUSH TABLES WITH READ LOCK
from "Waiting for release of readlock" to "Waiting for commit
lock".
mysql-test/t/flush_block_commit_notembedded.test:
Adjusted test case after changing thread state name which is
used when DML waits for FLUSH TABLES WITH READ LOCK. Now we
use "Waiting for global read lock" in this case.
mysql-test/t/flush_read_lock.test:
Added test coverage for various aspects of FLUSH TABLES WITH
READ LOCK functionality.
mysql-test/t/flush_read_lock_kill-master.opt:
We no longer need to use make_global_read_lock_block_commit_loop
debug tag in this test. Instead we rely on an appropriate
debug_sync point in MDL code.
mysql-test/t/flush_read_lock_kill.test:
Adjusted test case after replacing custom global read lock
implementation with one based on metadata locks. Use new
debug_sync point. Do not disable concurrent inserts as now
InnoDB we always use InnoDB table.
mysql-test/t/lock_multi.test:
Adjusted test case after changing thread state names which
are used when DML or DDL waits for FLUSH TABLES WITH READ
LOCK to "Waiting for global read lock".
mysql-test/t/mdl_sync.test:
Adjusted test case after replacing custom global read lock
implementation with one based on metadata locks. Replaced
usage of GRL-specific debug_sync's with appropriate sync
points in MDL subsystem. Updated thread state names which
are used when DDL waits for FTWRL.
mysql-test/t/trigger_notembedded.test:
Adjusted test case after changing thread state names which
are used when DML or DDL waits for FLUSH TABLES WITH READ
LOCK to "Waiting for global read lock".
sql/event_data_objects.cc:
Removed Event_queue_element::status/last_executed_changed
members and Event_queue_element::update_timing_fields()
method. We no longer use this class for updating mysql.events
once event is chosen for execution. Accesses to instances of
this class in scheduler thread require protection by
Event_queue::LOCK_event_queue mutex and we try to avoid
updating table while holding this lock.
sql/event_data_objects.h:
Removed Event_queue_element::status/last_executed_changed
members and Event_queue_element::update_timing_fields()
method. We no longer use this class for updating mysql.events
once event is chosen for execution. Accesses to instances of
this class in scheduler thread require protection by
Event_queue::LOCK_event_queue mutex and we try to avoid
updating table while holding this lock.
sql/event_db_repository.cc:
- Changed Event_db_repository methods to not release all
metadata locks once they are done updating mysql.events
table. This allows to keep metadata lock protecting
against GRL and lock protecting particular event around
until corresponding DDL statement is written to the binary
log.
- Removed logic for conditional update of "status" and
"last_executed" fields from update_timing_fields_for_event()
method. In the only case when this method is called now
"last_executed" is always modified and tracking change
of "status" is too much hassle.
sql/event_db_repository.h:
Removed logic for conditional update of "status" and
"last_executed" fields from Event_db_repository::
update_timing_fields_for_event() method.
In the only case when this method is called now "last_executed"
is always modified and tracking change of "status" field is
too much hassle.
sql/event_queue.cc:
Changed event scheduler code not to update mysql.events
table while holding Event_queue::LOCK_event_queue mutex.
Doing so led to a deadlock with a new GRL implementation.
This deadlock didn't occur with old implementation due to
fact that code acquiring protection against GRL ignored
pending GRL requests (which lead to GRL starvation).
One of goals of new implementation is to disallow GRL
starvation and so we have to solve problem with this
deadlock in a different way.
sql/events.cc:
Changed methods of Events class to acquire protection
against GRL while perfoming DDL statement and keep it
until statement is written to the binary log.
Unfortunately this step together with new GRL implementation
exposed deadlock involving Events::LOCK_event_metadata
and GRL. To solve it Events::LOCK_event_metadata mutex was
replaced with a metadata lock on event. As a side-effect
events DDL has to be prohibited under LOCK TABLES even in
cases when mysql.events table was explicitly locked for
write.
sql/events.h:
Replaced Events::LOCK_event_metadata mutex with a metadata
lock on event.
sql/ha_ndbcluster.cc:
Updated code after replacing custom global read lock
implementation with one based on MDL. Since MDL subsystem
should now be able to detect deadlocks involving metadata
locks and GRL there is no need for special handling of
active GRL.
sql/handler.cc:
Replaced custom implementation of global read lock with
one based on metadata locks. Consequently when doing
commit instead of calling method of Global_read_lock
class to acquire protection against GRL we simply acquire
IX in COMMIT namespace.
sql/lock.cc:
Replaced custom implementation of global read lock with
one based on metadata locks. This step allows to expose
wait for GRL to deadlock detector of MDL subsystem and
thus succesfully resolve deadlocks similar to one behind
bug #57006 "Deadlock between HANDLER and FLUSH TABLES
WITH READ LOCK". It also solves problem with GRL starvation
described in bug #54673 "It takes too long to get readlock
for 'FLUSH TABLES WITH READ LOCK'" since metadata locks used
by GRL give preference to FTWRL statement instead of DML
statements (if needed in future this can be changed to
fair scheduling).
Similar to old implementation of acquisition of GRL is
two-step. During the first step we block all concurrent
DML and DDL statements by acquiring global S metadata lock
(each DML and DDL statement acquires global IX lock for
its duration). During the second step we block commits by
acquiring global S lock in COMMIT namespace (commit code
acquires global IX lock in this namespace).
Note that unlike in old implementation acquisition of
protection against GRL in DML and DDL is semi-automatic.
We assume that any statement which should be blocked by GRL
will either open and acquires write-lock on tables or acquires
metadata locks on objects it is going to modify. For any such
statement global IX metadata lock is automatically acquired
for its duration.
To support this change:
- Global_read_lock::lock/unlock_global_read_lock and
make_global_read_lock_block_commit methods were changed
accordingly.
- Global_read_lock::wait_if_global_read_lock() and
start_waiting_global_read_lock() methods were dropped.
It is now responsibility of code acquiring metadata locks
opening tables to acquire protection against GRL by
explicitly taking global IX lock with statement duration.
- Global variables, mutex and condition variable used by
old implementation was removed.
- lock_routine_name() was changed to use statement duration for
its global IX lock. It was also renamed to lock_object_name()
as it now also used to take metadata locks on events.
- Global_read_lock::set_explicit_lock_duration() was added which
allows not to release locks used for GRL when leaving prelocked
mode.
sql/lock.h:
- Renamed lock_routine_name() to lock_object_name() and changed
its signature to allow its usage for events.
- Removed broadcast_refresh() function. It is no longer needed
with new GRL implementation.
sql/log_event.cc:
Release metadata locks with statement duration at the end
of processing legacy event for LOAD DATA. This ensures that
replication thread processing such event properly releases
its protection against global read lock.
sql/mdl.cc:
Changed MDL subsystem to support new MDL-based implementation
of global read lock.
Added COMMIT and EVENTS namespaces for metadata locks. Changed
thread state name for GLOBAL namespace to "Waiting for global
read lock".
Optimized MDL_map::find_or_insert() method to avoid taking
m_mutex mutex when looking up MDL_lock objects for GLOBAL
or COMMIT namespaces. We keep pre-created MDL_lock objects
for these namespaces around and simply return pointers to
these global objects when needed.
Changed MDL_lock/MDL_scoped_lock to properly handle
notification of insert delayed handler threads when FTWRL
takes global S lock.
Introduced concept of lock duration. In addition to locks with
transaction duration which work in the way which is similar to
how locks worked before (i.e. they are released at the end of
transaction), locks with statement and explicit duration were
introduced.
Locks with statement duration are automatically released at the
end of statement. Locks with explicit duration require explicit
release and obsolete concept of transactional sentinel.
* Changed MDL_request and MDL_ticket classes to support notion
of duration.
* Changed MDL_context to keep locks with different duration in
different lists. Changed code handling ticket list to take
this into account.
* Changed methods responsible for releasing locks to take into
account duration of tickets. Particularly public
MDL_context::release_lock() method now only can release
tickets with explicit duration (there is still internal
method which allows to specify duration). To release locks
with statement or transaction duration one have to use
release_statement/transactional_locks() methods.
* Concept of savepoint for MDL subsystem now has to take into
account locks with statement duration. Consequently
MDL_savepoint class was introduced and methods working with
savepoints were updated accordingly.
* Added methods which allow to set duration for one or all
locks in the context.
sql/mdl.h:
Changed MDL subsystem to support new MDL-based implementation
of global read lock.
Added COMMIT and EVENTS namespaces for metadata locks.
Introduced concept of lock duration. In addition to locks with
transaction duration which work in the way which is similar to
how locks worked before (i.e. they are released at the end of
transaction), locks with statement and explicit duration were
introduced.
Locks with statement duration are automatically released at the
end of statement. Locks with explicit duration require explicit
release and obsolete concept of transactional sentinel.
* Changed MDL_request and MDL_ticket classes to support notion
of duration.
* Changed MDL_context to keep locks with different duration in
different lists. Changed code handling ticket list to take
this into account.
* Changed methods responsible for releasing locks to take into
account duration of tickets. Particularly public
MDL_context::release_lock() method now only can release
tickets with explicit duration (there is still internal
method which allows to specify duration). To release locks
with statement or transaction duration one have to use
release_statement/transactional_locks() methods.
* Concept of savepoint for MDL subsystem now has to take into
account locks with statement duration. Consequently
MDL_savepoint class was introduced and methods working with
savepoints were updated accordingly.
* Added methods which allow to set duration for one or all
locks in the context.
sql/mysqld.cc:
Removed global mutex and condition variables which were used
by old implementation of GRL.
Also we no longer need to initialize Events::LOCK_event_metadata
mutex as it was replaced with metadata locks on events.
sql/mysqld.h:
Removed global variable, mutex and condition variables which
were used by old implementation of GRL.
sql/rpl_rli.cc:
When slave thread closes tables which were open for handling
of RBR events ensure that it releases global IX lock which
was acquired as protection against GRL.
sql/sp.cc:
Adjusted code to the new signature of lock_object/routine_name(),
to the fact that one now needs specify duration of lock when
initializing MDL_request and to the fact that savepoints for MDL
subsystem are now represented by MDL_savepoint class.
sql/sp_head.cc:
Ensure that statements in stored procedures release statement
metadata locks and thus release their protectiong against GRL
in proper moment in time.
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/sql_admin.cc:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/sql_base.cc:
- Implemented support for new approach to acquiring protection
against global read lock. We no longer acquire such protection
explicitly on the basis of statement flags. Instead we always
rely on code which is responsible for acquiring metadata locks
on object to be changed acquiring this protection. This is
achieved by acquiring global IX metadata lock with statement
duration. Code doing this also responsible for checking that
current connection has no active GRL by calling an
Global_read_lock::can_acquire_protection() method.
Changed code in open_table() and lock_table_names()
accordingly.
Note that as result of this change DDL and DML on temporary
tables is always compatible with GRL (before it was
incompatible in some cases and compatible in other cases).
- To speed-up code acquiring protection against GRL introduced
m_has_protection_against_grl member in Open_table_context
class. It indicates that protection was already acquired
sometime during open_tables() execution and new attempts
can be skipped.
- Thanks to new GRL implementation calls to broadcast_refresh()
became unnecessary and were removed.
- Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request and to the fact that
savepoints for MDL subsystem are now represented by
MDL_savepoint class.
sql/sql_base.h:
Adjusted code to the fact that savepoints for MDL subsystem are
now represented by MDL_savepoint class.
Also introduced Open_table_context::m_has_protection_against_grl
member which allows to avoid acquiring protection against GRL
while opening tables if such protection was already acquired.
sql/sql_class.cc:
Changed THD::leave_locked_tables_mode() after transactional
sentinel for metadata locks was obsoleted by introduction of
locks with explicit duration.
sql/sql_class.h:
- Adjusted code to the fact that savepoints for MDL subsystem
are now represented by MDL_savepoint class.
- Changed Global_read_lock class according to changes in
global read lock implementation:
* wait_if_global_read_lock and start_waiting_global_read_lock
are now gone. Instead code needing protection against GRL
has to acquire global IX metadata lock with statement
duration itself. To help it new can_acquire_protection()
was introduced. Also as result of the above change
m_protection_count member is gone too.
* Added m_mdl_blocks_commits_lock member to store metadata
lock blocking commits.
* Adjusted code to the fact that concept of transactional
sentinel was obsoleted by concept of lock duration.
- Removed CF_PROTECT_AGAINST_GRL flag as it is no longer
necessary. New GRL implementation acquires protection
against global read lock automagically when statement
acquires metadata locks on tables or other objects it
is going to change.
sql/sql_db.cc:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/sql_handler.cc:
Removed call to broadcast_refresh() function. It is no longer
needed with new GRL implementation.
Adjusted code after introducing duration concept for metadata
locks. Particularly to the fact transactional sentinel was
replaced with explicit duration.
sql/sql_handler.h:
Renamed mysql_ha_move_tickets_after_trans_sentinel() to
mysql_ha_set_explicit_lock_duration() after transactional
sentinel was obsoleted by locks with explicit duration.
sql/sql_insert.cc:
Adjusted code handling delaying inserts after switching to
new GRL implementation. Now connection thread initiating
delayed insert has to acquire global IX lock in addition
to metadata lock on table being inserted into. This IX lock
protects against GRL and similarly to SW lock on table being
inserted into has to be passed to handler thread in order to
avoid deadlocks.
sql/sql_lex.cc:
LEX::protect_against_global_read_lock member is no longer
necessary since protection against GRL is automatically
taken by code acquiring metadata locks/opening tables.
sql/sql_lex.h:
LEX::protect_against_global_read_lock member is no longer
necessary since protection against GRL is automatically
taken by code acquiring metadata locks/opening tables.
sql/sql_parse.cc:
- Implemented support for new approach to acquiring protection
against global read lock. We no longer acquire such protection
explicitly on the basis of statement flags. Instead we always
rely on code which is responsible for acquiring metadata locks
on object to be changed acquiring this protection. This is
achieved by acquiring global IX metadata lock with statement
duration. This lock is automatically released at the end of
statement execution.
- Changed implementation of CREATE/DROP PROCEDURE/FUNCTION not
to release metadata locks and thus protection against of GRL
in the middle of statement execution.
- Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request and to the fact that
savepoints for MDL subsystem are now represented by
MDL_savepoint class.
sql/sql_prepare.cc:
Adjusted code to the to the fact that savepoints for MDL
subsystem are now represented by MDL_savepoint class.
sql/sql_rename.cc:
With new GRL implementation there is no need to explicitly
acquire protection against GRL before renaming tables.
This happens automatically in code which acquires metadata
locks on tables being renamed.
sql/sql_show.cc:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request and to the fact that
savepoints for MDL subsystem are now represented by
MDL_savepoint class.
sql/sql_table.cc:
- With new GRL implementation there is no need to explicitly
acquire protection against GRL before dropping tables.
This happens automatically in code which acquires metadata
locks on tables being dropped.
- Changed mysql_alter_table() not to release lock on new table
name explicitly and to rely on automatic release of locks
at the end of statement instead. This was necessary since
now MDL_context::release_lock() is supported only for locks
for explicit duration.
sql/sql_trigger.cc:
With new GRL implementation there is no need to explicitly
acquire protection against GRL before changing table triggers.
This happens automatically in code which acquires metadata
locks on tables which triggers are to be changed.
sql/sql_update.cc:
Fix bug exposed by GRL testing. During prepare phase acquire
only S metadata locks instead of SW locks to keep prepare of
multi-UPDATE compatible with concurrent LOCK TABLES WRITE
and global read lock.
sql/sql_view.cc:
With new GRL implementation there is no need to explicitly
acquire protection against GRL before creating view.
This happens automatically in code which acquires metadata
lock on view to be created.
sql/sql_yacc.yy:
LEX::protect_against_global_read_lock member is no longer
necessary since protection against GRL is automatically
taken by code acquiring metadata locks/opening tables.
sql/table.cc:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/table.h:
Adjusted code to the fact that one now needs specify duration
of lock when initializing MDL_request.
sql/transaction.cc:
Replaced custom implementation of global read lock with
one based on metadata locks. Consequently when doing
commit instead of calling method of Global_read_lock
class to acquire protection against GRL we simply acquire
IX in COMMIT namespace.
Also adjusted code to the fact that MDL savepoint is now
represented by MDL_savepoint class.
bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ
LOCK" and bug #54673 "It takes too long to get readlock for
'FLUSH TABLES WITH READ LOCK'".
The first bug manifested itself as a deadlock which occurred
when a connection, which had some table open through HANDLER
statement, tried to update some data through DML statement
while another connection tried to execute FLUSH TABLES WITH
READ LOCK concurrently.
What happened was that FTWRL in the second connection managed
to perform first step of GRL acquisition and thus blocked all
upcoming DML. After that it started to wait for table open
through HANDLER statement to be flushed. When the first connection
tried to execute DML it has started to wait for GRL/the second
connection creating deadlock.
The second bug manifested itself as starvation of FLUSH TABLES
WITH READ LOCK statements in cases when there was a constant
stream of concurrent DML statements (in two or more
connections).
This has happened because requests for protection against GRL
which were acquired by DML statements were ignoring presence of
pending GRL and thus the latter was starved.
This patch solves both these problems by re-implementing GRL
using metadata locks.
Similar to the old implementation acquisition of GRL in new
implementation is two-step. During the first step we block
all concurrent DML and DDL statements by acquiring global S
metadata lock (each DML and DDL statement acquires global IX
lock for its duration). During the second step we block commits
by acquiring global S lock in COMMIT namespace (commit code
acquires global IX lock in this namespace).
Note that unlike in old implementation acquisition of
protection against GRL in DML and DDL is semi-automatic.
We assume that any statement which should be blocked by GRL
will either open and acquires write-lock on tables or acquires
metadata locks on objects it is going to modify. For any such
statement global IX metadata lock is automatically acquired
for its duration.
The first problem is solved because waits for GRL become
visible to deadlock detector in metadata locking subsystem
and thus deadlocks like one in the first bug become impossible.
The second problem is solved because global S locks which
are used for GRL implementation are given preference over
IX locks which are acquired by concurrent DML (and we can
switch to fair scheduling in future if needed).
Important change:
FTWRL/GRL no longer blocks DML and DDL on temporary tables.
Before this patch behavior was not consistent in this respect:
in some cases DML/DDL statements on temporary tables were
blocked while in others they were not. Since the main use cases
for FTWRL are various forms of backups and temporary tables are
not preserved during backups we have opted for consistently
allowing DML/DDL on temporary tables during FTWRL/GRL.
Important change:
This patch changes thread state names which are used when
DML/DDL of FTWRL is waiting for global read lock. It is now
either "Waiting for global read lock" or "Waiting for commit
lock" depending on the stage on which FTWRL is.
Incompatible change:
To solve deadlock in events code which was exposed by this
patch we have to replace LOCK_event_metadata mutex with
metadata locks on events. As result we have to prohibit
DDL on events under LOCK TABLES.
This patch also adds extensive test coverage for interaction
of DML/DDL and FTWRL.
Performance of new and old global read lock implementations
in sysbench tests were compared. There were no significant
difference between new and old implementations.
Added locking of lock mutex when updating status in external_unlock() for Aria and MyISAM tables.
Fixed that 'source' command doesn't cause mysql command line tool to exit on error.
DEBUG_EXECUTE() and DEBUG_EVALUATE_IF() should not execute things based on wildcards. (Allows one to run --debug with mysql-test-run scripts that uses @debug)
Fixed several core dump, deadlock and crashed table bugs in handling of LOCK TABLE with MERGE tables:
- Added priority of locks to avoid crashes with MERGE tables.
- Added thr_lock_merge() to allow one to merge two results of thr_lock().
Fixed 'not found row' bug in REPLACE with Aria tables.
Mark MyISAM tables that are part of MERGE with HA_OPEN_MERGE_TABLE and set the locks to have priority THR_LOCK_MERGE_PRIV.
- By sorting MERGE tables last in thr_multi_unlock() it's safer to release and relock them many times (can happen when TRIGGERS are created)
Avoid printing (null) in debug file (to easier find out wrong NULL pointer usage with %s).
client/mysql.cc:
Fixed that 'source' command doesn't cause mysql command line tool to exit on error.
client/mysqltest.cc:
Don't send NULL to fn_format(). (Can cause crash on Solaris when using --debug)
dbug/dbug.c:
DEBUG_EXECUTE() and DEBUG_EVALUATE_IF() should not execute things based on wildcards.
include/my_base.h:
Added flag to signal if one opens a MERGE table.
Added extra() command to signal that one is not part of a MERGE table anymore.
include/thr_lock.h:
Added priority for locks (needed to fix bug in thr_lock when using MERGE tables)
Added option to thr_unlock() if get_status() should be called.
Added prototype for thr_merge_locks().
mysql-test/mysql-test-run.pl:
Ignore crashed table warnings for tables named 'crashed'.
mysql-test/r/merge.result:
Renamed triggers to make debugging easier.
Added some CHECK TABLES to catch errors earlier.
Additional tests.
mysql-test/r/merge_debug.result:
Test of error handling when reopening MERGE tables.
mysql-test/r/udf_query_cache.result:
Added missing flush status
mysql-test/suite/parts/r/partition_repair_myisam.result:
Update results
mysql-test/t/merge.test:
Renamed triggers to make debugging easier.
Added some CHECK TABLES to catch errors earlier.
Additional tests.
mysql-test/t/merge_debug.test:
Test of error handling when reopening MERGE tables.
mysql-test/t/udf_query_cache.test:
Added missing flush status
mysys/my_getopt.c:
Removed not used variable
mysys/my_symlink2.c:
Changed (null) to (NULL) to make it easier to find NULL arguments to DBUG_PRINT() functions.
(On linux, NULL to sprintf is printed 'null')
mysys/thr_lock.c:
Added priority of locks to avoid crashes with MERGE tables.
Added thr_lock_merge() to allow one to merge two results of thr_lock().
- This is needed for MyISAM as all locked table must share the same status. If not, you will not see newly inserted rows in other instances of the table.
If calling thr_unlock() with THR_UNLOCK_UPDATE_STATUS, call update_status() and restore_status() for the locks. This is needed in some rare cases where we call thr_unlock() followed by thr_lock() without calling external_unlock/external_lock in between.
Simplify loop in thr_multi_lock().
Added 'start_trans', which is called at end of thr_multi_lock() when all locks are taken.
- This was needed by Aria to ensure that transaction is started when we got all locks, not at get_status(). Without this, some rows could not be visible when we lock two tables at the same time, causing REPLACE using two tables to fail unexpectedly.
sql/handler.cc:
Add an assert() in handler::print_error() for "impossible errors" (like table is crashed) when --debug-assert-if-crashed-table is used.
sql/lock.cc:
Simplify mysql_lock_tables() code if get_lock_data() returns 0 locks.
Added new parameter to thr_multi_unlock()
In mysql_unlock_read_tables(), call first externa_unlock(), then thr_multi_unlock(); This is same order as we do in mysql_unlock_tables().
Don't abort locks in mysql_lock_abort() for merged tables when a MERGE table is deleted; Would cause a spin lock.
Added call to thr_merge_locks() in mysql_lock_merge() to ensure consistency in thr_locks().
- New locks of same type and table is stored after the old lock to ensure that we get the status from the original lock.
sql/mysql_priv.h:
Added debug_assert_if_crashed_table
sql/mysqld.cc:
Added --debug-assert-if-crashed-table
sql/parse_file.cc:
Don't print '(null)' in DBUG_PRINT of no dir given
sql/set_var.cc:
Increase default size of buffer for @debug variable.
sql/sql_base.cc:
In case of error from reopen_table() in reopen_tables(), call unlock_open_table() and restart loop.
- This fixed bug when we twice deleted same table from open_cache.
Don't take name lock for already name locked table in open_unireg_entry().
- Fixed bug when doing repair in reopen_table().
- In detach_merge_children(), always detach if 'clear_refs' is given. We can't trust parent->children_attached as this function can be called twice, first time with clear_refs set to 0.
sql/sql_class.cc:
Changed printing of (null) to "" in set_thd_proc_info()
sql/sql_parse.cc:
Added DBUG
sql/sql_trigger.cc:
Don't call unlink_open_table() if reopen_table() fails as the table may already be freed.
storage/maria/ma_bitmap.c:
Fixed DBUG_ASSERT() in allocate_tail()
storage/maria/ma_blockrec.c:
Fixed wrong calculation of row length for very small rows in undo_row_update().
- Fixes ASSERT() when doing undo.
storage/maria/ma_blockrec.h:
Added _ma_block_start_trans() and _ma_block_start_trans_no_versioning()
storage/maria/ma_locking.c:
Call _ma_update_status_with_lock() when releasing write locks.
- Fixes potential problem with updating status without the proper lock.
storage/maria/ma_open.c:
Changed to use start_trans() instead of get_status() to ensure that we see all rows in all locked tables when we got the locks.
- Fixed 'not found row' bug in REPLACE with Aria tables.
storage/maria/ma_state.c:
Added _ma_update_status_with_lock() and _ma_block_start_trans().
This is to ensure that we see all rows in all locked tables when we got the locks.
storage/maria/ma_state.h:
Added _ma_update_status_with_lock()
storage/maria/ma_write.c:
More DBUG_PRINT
storage/myisam/mi_check.c:
Fixed error message
storage/myisam/mi_extra.c:
Added HA_EXTRA_DETACH_CHILD:
- Detach MyISAM table to not be part of MERGE table (remove flag & lock priority).
storage/myisam/mi_locking.c:
Call mi_update_status_with_lock() when releasing write locks.
- Fixes potential problem with updating status without the proper lock.
Change to use new HA_OPEN_MERGE_TABLE flag to test if MERGE table.
Added mi_fix_status(), called by thr_merge().
storage/myisam/mi_open.c:
Added marker if part of MERGE table.
Call mi_fix_status() in thr_lock() for transactional tables.
storage/myisam/myisamdef.h:
Change my_once_flag to uint, as it stored different values than just 0/1
Added 'open_flag' to store state given to mi_open()
storage/myisammrg/ha_myisammrg.cc:
Add THR_LOCK_MERGE_PRIV to THR_LOCK_DATA to get MERGE locks sorted after other types of locks.
storage/myisammrg/myrg_locking.c:
Remove windows specific code.
storage/myisammrg/myrg_open.c:
Use HA_OPEN_MERGE_TABLE to mi_open().
Set HA_OPEN_MERGE_TABLE for linked MyISAM tables.
storage/xtradb/buf/buf0buf.c:
Fixed compiler warning
storage/xtradb/buf/buf0lru.c:
Initialize variable that could be used not initialized.
"Grantor" columns' data is lost when replicating mysql.tables_priv.
Slave SQL thread used its default user ''@'' as the grantor of GRANT|REVOKE
statements executing on it.
In this patch, current user is put in query log event for all GRANT and REVOKE
statement, SQL thread uses the user in query log event as grantor.
mysql-test/suite/rpl/r/rpl_do_grant.result:
Add test for this bug.
mysql-test/suite/rpl/t/rpl_do_grant.test:
Add test for this bug.
sql/log_event.cc:
Refactoring THD::current_user_used and related functions.
current_user_used is used to judge if current user should be
binlogged in query log event. So it is better to call it m_binlog_invoker.
The related functions are renamed too.
sql/sql_class.cc:
Refactoring THD::current_user_used and related functions.
current_user_used is used to judge if current user should be
binlogged in query log event. So it is better to call it m_binlog_invoker.
The related functions are renamed too.
sql/sql_class.h:
Refactoring THD::current_user_used and related functions.
current_user_used is used to judge if current user should be
binlogged in query log event. So it is better to call it m_binlog_invoker.
The related functions are renamed too.
sql/sql_parse.cc:
Call binlog_invoker() for GRANT and REVOKE statements.
"Grantor" columns' data is lost when replicating mysql.tables_priv.
Slave SQL thread used its default user ''@'' as the grantor of GRANT|REVOKE
statements executing on it.
In this patch, current user is put in query log event for all GRANT and REVOKE
statement, SQL thread uses the user in query log event as grantor.
- A prerequisite cleanup patch for making KILL reliable.
The test case main.kill did not work reliably.
The following problems have been identified:
1. A kill signal could go lost if it came in, short before a
thread went reading on the client connection.
2. A kill signal could go lost if it came in, short before a
thread went waiting on a condition variable.
These problems have been solved as follows. Please see also
added code comments for more details.
1. There is no safe way to detect, when a thread enters the
blocking state of a read(2) or recv(2) system call, where it
can be interrupted by a signal. Hence it is not possible to
wait for the right moment to send a kill signal. It has been
decided, not to fix it in the code. Instead, the test case
repeats the KILL statement until the connection terminates.
2. Before waiting on a condition variable, we register it
together with a synchronizating mutex in THD::mysys_var. After
this, we need to test THD::killed again. At some places we did
only test it in a loop condition before the registration. When
THD::killed had been set between this test and the registration,
we entered waiting without noticing the killed flag. Additional
checks ahve been introduced where required.
In addition to the above, a re-write of the main.kill test
case has been done. All sleeps have been replaced by Debug
Sync Facility synchronization. A couple of sync points have
been added to the server code.
To avoid further problems, if the test case fails in spite of
the fixes, the test case has been added to the "experimental"
list for now.
- Most of the work on this patch is authored by Ingo Struewing
mysql-test/t/kill.test:
Re-wrote test case to use Debug Sync points instead of sleeps
sql/event_queue.cc:
Fixed kill detection in Event_queue::cond_wait() by adding a check
after enter_cond().
sql/lock.cc:
Moved Debug Sync points behind enter_cond().
Fixed comments.
sql/slave.cc:
Fixed kill detection in start_slave_thread() by adding a check
after enter_cond().
sql/sql_class.cc:
Swapped order of kill and close in THD::awake().
Added comments.
sql/sql_class.h:
Added a comment to THD::killed.
sql/sql_parse.cc:
Added a sync point in do_command().
sql/sql_select.cc:
Added a sync point in JOIN::optimize().
- A prerequisite cleanup patch for making KILL reliable.
The test case main.kill did not work reliably.
The following problems have been identified:
1. A kill signal could go lost if it came in, short before a
thread went reading on the client connection.
2. A kill signal could go lost if it came in, short before a
thread went waiting on a condition variable.
These problems have been solved as follows. Please see also
added code comments for more details.
1. There is no safe way to detect, when a thread enters the
blocking state of a read(2) or recv(2) system call, where it
can be interrupted by a signal. Hence it is not possible to
wait for the right moment to send a kill signal. It has been
decided, not to fix it in the code. Instead, the test case
repeats the KILL statement until the connection terminates.
2. Before waiting on a condition variable, we register it
together with a synchronizating mutex in THD::mysys_var. After
this, we need to test THD::killed again. At some places we did
only test it in a loop condition before the registration. When
THD::killed had been set between this test and the registration,
we entered waiting without noticing the killed flag. Additional
checks ahve been introduced where required.
In addition to the above, a re-write of the main.kill test
case has been done. All sleeps have been replaced by Debug
Sync Facility synchronization. A couple of sync points have
been added to the server code.
To avoid further problems, if the test case fails in spite of
the fixes, the test case has been added to the "experimental"
list for now.
- Most of the work on this patch is authored by Ingo Struewing
set to 128k.
sql/sp.cc:
Added checking for stack overrun at functions
db_load_routine/sp_find_routine.
sql/sp_head.cc:
sp_head::execute() modified: pass constant value STACK_MIN_SIZE
instead of 8 * STACK_MIN_SIZE as second argument value
in call to check_stack_overrun. Added checking for stack overrun
at functions sp_lex_keeper::reset_lex_and_exec_core/sp_instr_stmt::execute.
sql/sql_parse.cc:
check_stack_overrun modified: allocate buffer for error message
at heap instead of stack.
parse_sql modified: added call to check_stack_overrun() before
parsing of sql statement.
Now the actual binlog position for each commit is stored in THD, and XtraDB
can fetch the correct value from within commit_ordered() or commit().
mysql-test/r/group_commit_binlog_pos.result:
Test case for XtraDB binlog position.
mysql-test/t/group_commit_binlog_pos-master.opt:
Test case for XtraDB binlog position.
mysql-test/t/group_commit_binlog_pos.test:
Test case for XtraDB binlog position.
sql/log.cc:
Save binlog position corresponding to commit in THD, and make accessible to storage engine.
sql/sql_parse.cc:
Add generic crash point for use in test cases.
storage/xtradb/handler/ha_innodb.cc:
Update to use new method of getting current binlog position that works with group commit.
storage/xtradb/handler/ha_innodb.h:
Update to use new method of getting current binlog position that works with group commit.
replication aborts
When recieving a 'SLAVE STOP' command, slave SQL thread will roll back the
transaction and stop immidiately if there is only transactional table updated,
even through 'CREATE|DROP TEMPOARY TABLE' statement are in it. But These
statements can never be rolled back. Because the temporary tables to the user
session mapping remain until 'RESET SLAVE', Therefore it will abort SQL thread
with an error that the table already exists or doesn't exist, when it restarts
and executes the whole transaction again.
After this patch, SQL thread always waits till the transaction ends and then stops,
if 'CREATE|DROP TEMPOARY TABLE' statement are in it.
mysql-test/extra/rpl_tests/rpl_stop_slave.test:
Auxiliary file which is used to test this bug.
mysql-test/suite/rpl/t/rpl_stop_slave.test:
Test case for this bug.
sql/slave.cc:
Checking if OPTION_KEEP_LOG is set. If it is set, SQL thread should wait
until the transaction ends.
sql/sql_parse.cc:
Add a debug point for testing this bug.
replication aborts
When recieving a 'SLAVE STOP' command, slave SQL thread will roll back the
transaction and stop immidiately if there is only transactional table updated,
even through 'CREATE|DROP TEMPOARY TABLE' statement are in it. But These
statements can never be rolled back. Because the temporary tables to the user
session mapping remain until 'RESET SLAVE', Therefore it will abort SQL thread
with an error that the table already exists or doesn't exist, when it restarts
and executes the whole transaction again.
After this patch, SQL thread always waits till the transaction ends and then stops,
if 'CREATE|DROP TEMPOARY TABLE' statement are in it.
sql/sql_parse.cc:
Make some not commonly used functions with big local variables to separate functions to make default stack usage smaller.
Decrease size of db_buff[] (Was bigger than needed)
Allocate current_global_status_var with malloc().
storage/maria/ha_maria.cc:
Don't allocate HA_CHECK on stack (it's > 100K)
storage/maria/ma_check.c:
Removed duplicated code
discover its existence".
The problem was that user without any privileges on
routine was able to find out whether it existed or not.
DROP FUNCTION and DROP PROCEDURE statements were
checking if routine being dropped existed and reported
ER_SP_DOES_NOT_EXIST error/warning before checking
if user had enough privileges to drop it.
This patch solves this problem by changing code not to
check if routine exists before checking if user has enough
privileges to drop it. Moreover we no longer perform this
check using a separate call instead we rely on
sp_drop_routine() returning SP_KEY_NOT_FOUND if routine
doesn't exist.
This change also simplifies one of upcoming patches
refactoring global read lock implementation.
mysql-test/r/grant.result:
Updated test case after fixing bug#57061 "User without
privilege on routine can discover its existence". Removed
DROP PROCEDURE/FUNCTION statements which have started to
fail after this fix (correctly). There is no need in
dropping routines in freshly created database anyway.
mysql-test/r/sp-security.result:
Added new test case for bug#57061 "User without privilege
on routine can discover its existence". Updated existing
tests according to new behaviour.
mysql-test/suite/funcs_1/r/innodb_storedproc_06.result:
Updated test case after fixing bug#57061 "User without
privilege on routine can discover its existence".
Now we drop routines under user which has enough
privileges to do so.
mysql-test/suite/funcs_1/r/memory_storedproc_06.result:
Updated test case after fixing bug#57061 "User without
privilege on routine can discover its existence".
Now we drop routines under user which has enough
privileges to do so.
mysql-test/suite/funcs_1/r/myisam_storedproc_06.result:
Updated test case after fixing bug#57061 "User without
privilege on routine can discover its existence".
Now we drop routines under user which has enough
privileges to do so.
mysql-test/suite/funcs_1/storedproc/storedproc_06.inc:
Updated test case after fixing bug#57061 "User without
privilege on routine can discover its existence".
Now we drop routines under user which has enough
privileges to do so.
mysql-test/t/grant.test:
Updated test case after fixing bug#57061 "User without
privilege on routine can discover its existence". Removed
DROP PROCEDURE/FUNCTION statements which have started to
fail after this fix (correctly). There is no need in
dropping routines in freshly created database anyway.
mysql-test/t/sp-security.test:
Added new test case for bug#57061 "User without privilege
on routine can discover its existence". Updated existing
tests according to new behaviour.
sql/sp.cc:
Removed sp_routine_exists_in_table() which is no longer
used.
sql/sp.h:
Removed sp_routine_exists_in_table() which is no longer
used.
sql/sql_parse.cc:
When dropping routine we no longer check if routine exists
before checking if user has enough privileges to do so.
Moreover we no longer perform this check using a separate
call instead we rely on sp_drop_routine() returning
SP_KEY_NOT_FOUND if routine doesn't exist.
discover its existence".
The problem was that user without any privileges on
routine was able to find out whether it existed or not.
DROP FUNCTION and DROP PROCEDURE statements were
checking if routine being dropped existed and reported
ER_SP_DOES_NOT_EXIST error/warning before checking
if user had enough privileges to drop it.
This patch solves this problem by changing code not to
check if routine exists before checking if user has enough
privileges to drop it. Moreover we no longer perform this
check using a separate call instead we rely on
sp_drop_routine() returning SP_KEY_NOT_FOUND if routine
doesn't exist.
This change also simplifies one of upcoming patches
refactoring global read lock implementation.
Bug#54678: InnoDB, TRUNCATE, ALTER, I_S SELECT, crash or deadlock
- Incompatible change: truncate no longer resorts to a row by
row delete if the storage engine does not support the truncate
method. Consequently, the count of affected rows does not, in
any case, reflect the actual number of rows.
- Incompatible change: it is no longer possible to truncate a
table that participates as a parent in a foreign key constraint,
unless it is a self-referencing constraint (both parent and child
are in the same table). To work around this incompatible change
and still be able to truncate such tables, disable foreign checks
with SET foreign_key_checks=0 before truncate. Alternatively, if
foreign key checks are necessary, please use a DELETE statement
without a WHERE condition.
Problem description:
The problem was that for storage engines that do not support
truncate table via a external drop and recreate, such as InnoDB
which implements truncate via a internal drop and recreate, the
delete_all_rows method could be invoked with a shared metadata
lock, causing problems if the engine needed exclusive access
to some internal metadata. This problem originated with the
fact that there is no truncate specific handler method, which
ended up leading to a abuse of the delete_all_rows method that
is primarily used for delete operations without a condition.
Solution:
The solution is to introduce a truncate handler method that is
invoked when the engine does not support truncation via a table
drop and recreate. This method is invoked under a exclusive
metadata lock, so that there is only a single instance of the
table when the method is invoked.
Also, the method is not invoked and a error is thrown if
the table is a parent in a non-self-referencing foreign key
relationship. This was necessary to avoid inconsistency as
some integrity checks are bypassed. This is inline with the
fact that truncate is primarily a DDL operation that was
designed to quickly remove all data from a table.
mysql-test/suite/innodb/t/innodb-truncate.test:
Add test cases for truncate and foreign key checks.
Also test that InnoDB resets auto-increment on truncate.
mysql-test/suite/innodb/t/innodb.test:
FK is not necessary, test is related to auto-increment.
Update error number, truncate is no longer invoked if
table is parent in a FK relationship.
mysql-test/suite/innodb/t/innodb_mysql.test:
Update error number, truncate is no longer invoked if
table is parent in a FK relationship.
Use delete instead of truncate, test is used to check
the interaction of FKs, triggers and delete.
mysql-test/suite/parts/inc/partition_check.inc:
Fix typo.
mysql-test/suite/sys_vars/t/foreign_key_checks_func.test:
Update error number, truncate is no longer invoked if
table is parent in a FK relationship.
mysql-test/t/mdl_sync.test:
Modify test case to reflect and ensure that truncate takes
a exclusive metadata lock.
mysql-test/t/trigger-trans.test:
Update error number, truncate is no longer invoked if
table is parent in a FK relationship.
sql/ha_partition.cc:
Reorganize the various truncate methods. delete_all_rows is now
passed directly to the underlying engines, so as truncate. The
code responsible for truncating individual partitions is moved
to ha_partition::truncate_partition, which is invoked when a
ALTER TABLE t1 TRUNCATE PARTITION p statement is executed.
Since the partition truncate no longer can be invoked via
delete, the bitmap operations are not necessary anymore. The
explicit reset of the auto-increment value is also removed
as the underlying engines are now responsible for reseting
the value.
sql/handler.cc:
Wire up the handler truncate method.
sql/handler.h:
Introduce and document the truncate handler method. It assumes
certain use cases of delete_all_rows.
Add method to retrieve the list of foreign keys referencing a
table. Method is used to avoid truncating tables that are
parent in a foreign key relationship.
sql/share/errmsg-utf8.txt:
Add error message for truncate and FK.
sql/sql_lex.h:
Introduce a flag so that the partition engine can detect when
a partition is being truncated. Used to give a special error.
sql/sql_parse.cc:
Function mysql_truncate_table no longer exists.
sql/sql_partition_admin.cc:
Implement the TRUNCATE PARTITION statement.
sql/sql_truncate.cc:
Change the truncate table implementation to use the new truncate
handler method and to not rely on row-by-row delete anymore.
The truncate handler method is always invoked with a exclusive
metadata lock. Also, it is no longer possible to truncate a
table that is parent in some non-self-referencing foreign key.
storage/archive/ha_archive.cc:
Rename method as the description indicates that in the future
this could be a truncate operation.
storage/blackhole/ha_blackhole.cc:
Implement truncate as no operation for the blackhole engine in
order to remain compatible with older releases.
storage/federated/ha_federated.cc:
Introduce truncate method that invokes delete_all_rows.
This is required to support partition truncate as this
form of truncate does not implement the drop and recreate
protocol.
storage/heap/ha_heap.cc:
Introduce truncate method that invokes delete_all_rows.
This is required to support partition truncate as this
form of truncate does not implement the drop and recreate
protocol.
storage/ibmdb2i/ha_ibmdb2i.cc:
Introduce truncate method that invokes delete_all_rows.
This is required to support partition truncate as this
form of truncate does not implement the drop and recreate
protocol.
storage/innobase/handler/ha_innodb.cc:
Rename delete_all_rows to truncate. InnoDB now does truncate
under a exclusive metadata lock.
Introduce and reorganize methods used to retrieve the list
of foreign keys referenced by a or referencing a table.
storage/myisammrg/ha_myisammrg.cc:
Introduce truncate method that invokes delete_all_rows.
This is required in order to remain compatible with earlier
releases where truncate would resort to a row-by-row delete.
Bug#54678: InnoDB, TRUNCATE, ALTER, I_S SELECT, crash or deadlock
- Incompatible change: truncate no longer resorts to a row by
row delete if the storage engine does not support the truncate
method. Consequently, the count of affected rows does not, in
any case, reflect the actual number of rows.
- Incompatible change: it is no longer possible to truncate a
table that participates as a parent in a foreign key constraint,
unless it is a self-referencing constraint (both parent and child
are in the same table). To work around this incompatible change
and still be able to truncate such tables, disable foreign checks
with SET foreign_key_checks=0 before truncate. Alternatively, if
foreign key checks are necessary, please use a DELETE statement
without a WHERE condition.
Problem description:
The problem was that for storage engines that do not support
truncate table via a external drop and recreate, such as InnoDB
which implements truncate via a internal drop and recreate, the
delete_all_rows method could be invoked with a shared metadata
lock, causing problems if the engine needed exclusive access
to some internal metadata. This problem originated with the
fact that there is no truncate specific handler method, which
ended up leading to a abuse of the delete_all_rows method that
is primarily used for delete operations without a condition.
Solution:
The solution is to introduce a truncate handler method that is
invoked when the engine does not support truncation via a table
drop and recreate. This method is invoked under a exclusive
metadata lock, so that there is only a single instance of the
table when the method is invoked.
Also, the method is not invoked and a error is thrown if
the table is a parent in a non-self-referencing foreign key
relationship. This was necessary to avoid inconsistency as
some integrity checks are bypassed. This is inline with the
fact that truncate is primarily a DDL operation that was
designed to quickly remove all data from a table.
sql/field.cc:
Remove feature of 'new_mode' that was never implemtented in a newer MySQL version.
sql/item_cmpfunc.cc:
Boyer more is stable; Don't have to be protected by --skip-new anymore
sql/mysqld.cc:
Don't disable some proven stable functions with --skip-new
sql/records.cc:
Don't disable record caching with --safe-mode anymore
sql/sql_delete.cc:
Do fast truncate even if --skip-new or --safe is used
sql/sql_parse.cc:
Use always mysql_optimizer() for optimizer (instead of mysql_recreate_table() in case of --safe or --skip-new)
sql/sql_select.cc:
Don't disable 'only_eq_ref_tables' if --safe is used.
sql/sql_yacc.yy:
Removed not meaningfull test of --old
REPAIR of merge table
Bug #56422 CHECK TABLE run when the table is locked reports
corruption along with timeout
The crash happened if a table maintenance statement (ANALYZE TABLE,
REPAIR TABLE, etc.) was executed on a MERGE table and opening and
locking a child table failed. This could for example happen if a child
table did not exist or if a lock timeout happened while waiting for
a conflicting metadata lock to disappear.
Since opening and locking the MERGE table and its children failed,
the tables would be closed and the metadata locks released.
However, TABLE_LIST::table for the MERGE table would still be set,
with its value invalid since the tables had been closed.
This caused the table maintenance statement to try to continue
and upgrade the metadata lock on the MERGE table. But since the lock
already had been released, this caused a segfault.
This patch fixes the problem by setting TABLE_LIST::table to NULL
if open_and_lock_tables() fails. This prevents maintenance
statements from continuing and trying to upgrade the metadata lock.
The patch includes a 5.5 version of the fix for
Bug #46339 crash on REPAIR TABLE merge table USE_FRM.
This bug caused REPAIR TABLE ... USE_FRM to give an assert
when used on merge tables.
The patch also enables the CHECK TABLE statement for log tables.
Before, CHECK TABLE for log tables gave ER_CANT_LOCK_LOG_TABLE,
yet still counted the statement as successfully executed.
With the changes to table maintenance statement error handling
in this patch, CHECK TABLE would no longer be considered as
successful in this case. This would have caused upgrade scripts
to mistakenly think that the general and slow logs are corrupted
and have to be repaired. Enabling CHECK TABLES for log tables
prevents this from happening.
Finally, the patch changes the error message from "Corrupt" to
"Operation failed" for a number of issues not related to table
corruption. For example "Lock wait timeout exceeded" and
"Deadlock found trying to get lock".
Test cases added to merge.test and check.test.
